JPH0715829B2 - Method for manufacturing sheet heating element - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing a sheet heating element used for a wide area heater, such as an electric carpet.

(Background Art) Conventionally, in a wide area heater such as an electric carpet of this type, as shown in FIG. 3, a heat-fusible resin such as low-density polyethylene is provided on both sides of a metal foil such as an aluminum foil. A heat-sensitive heating wire H in which a heat-fusible resin layer such as low-density polyethylene is also formed on the outermost layer surface of a heat spread sheet C with a film is wired in a predetermined pattern, and is heated and pressed to be integrated. It is generally known that after molding, the front surface material A and the back surface material B are attached to both surfaces thereof.

As shown in FIG. 4, the sheet heating element of this type has a metal foil 2
Since the heat-sensitive heating wires H are laid in a predetermined pattern on the heat-uniforming sheet having the heat-fusible resin layer 1 formed on both surfaces thereof, the heat-generating temperature is uniform over the entire surface and the temperature control operation is performed. It has the advantage of being stable.

More specifically, as shown in FIG. 5, the heat-sensitive heating wire used for this planar heating element is made by winding a heating wire 4 made of a copper alloy or the like around a winding core 3 made of polyester fiber in a spiral shape and then softening it. The resin layer 5 is covered by extrusion molding, the temperature detecting electrodes 6 of a copper alloy are spirally wound around the outer peripheral surface of the resin layer 5 at regular intervals, and further a polyester tape or the like is wound around the separation layer 7
After forming, cover the insulating layer 8 made of soft PVC,
A thermal adhesive layer 9 made of low-density polyethylene is adhered to the outermost surface of the outermost layer.

However, in the conventional sheet heating element, when the surface material A and the back surface material B are adhered to both sides of the electric carpet as shown in FIG. While the heat-sensitive heating wire H is extruded, the heat-sensitive heating wire H has a heat-shrinking action, and the front surface material A and the back surface material B also undergo heat shrinkage. There is a problem that a large "deflection" or a large "wrinkle" is generated in the metal foil 2 mainly in the direction intersecting the wiring direction of the heat-sensitive heating wire H, which makes the sitting comfort uncomfortable and the aesthetic appearance is poor. is doing.

Furthermore, when an electric carpet is used, the sheet is partially insulative and the temperature of the sheet heating element may rise to 80 to 90 ° C. Due to the thermal expansion of the foil 2 and the thermal contraction of the heat-sensitive heating wire H, similarly large "deflection" and large "wrinkle" may occur.

(Object of the Invention) The present invention has been proposed in view of the above points, and an object of the present invention is to completely prevent large "deflection" and large "wrinkle" occurring in the metal foil of the heat-soaking sheet. Another object of the present invention is to provide a method for manufacturing a sheet-like heat generating element that does not deform the heat-sensitive heating wire, does not cause adhesion failure, and shortens the bonding time.

(Disclosure of the Invention) Hereinafter, the present invention will be described with reference to the drawings.

FIG. 1 is an explanatory perspective view showing an embodiment of the present invention,
In the figure, D is a wiring board made of plywood, rubber or the like, H is a heat-sensitive heating wire, E is a support pin for supporting the heat-sensitive heating wire H along a wiring pattern, and 10 is arranged in parallel on the upper surface of the wiring board D. It is a protrusion.

In this wiring board D, a passage of a wiring pattern is formed by the protruding portion 10, and the heat-sensitive heating wire H is formed at the bending point of this passage.
The support pins E1 to E12 of the
Is provided with a pair of support pins E0, E13 for holding both ends of the.

The protrusions 10 arranged side by side on the wiring board D are preferably made of a material such as plywood or rubber, and the height thereof is substantially the same as the outer diameter of the heat-sensitive heating wire H. Furthermore, it is preferable to form the gap 11 at right angles to the longitudinal direction of the protrusion 10.

Next, a method of manufacturing the planar heating element will be described. One end of the heat-sensitive heating wire is held between a pair of support pins E0 provided at one corner of the wiring board D and sequentially provided along the passage. Support pin
Wirings are formed so that the heat-sensitive heating wires H are supported by the E1 to E12 so as to be hooked and the tip ends thereof are held between the other pair of support pins E13. Next, from above the wiring board D on which the heat-sensitive heating wires H are wired, the soaking sheet C having the heat-sealing layer 1 adhered to both surfaces of the metal foil 2 is overlapped and bonded by heating / pressing with a heat press. To produce a sheet heating element.

As shown in FIG. 2, in the sheet heating element having such a structure, innumerable fine wrinkles 12 are generated on the surface of the heat equalizing sheet C in the direction intersecting with the heat-sensitive heating line H. In particular, the protrusion
If the gap portion 11 is provided in 10, the fine wrinkles 12
Will occur. Since the fine wrinkles generated in the gap 11 grow a little larger, it is preferable that the gap 11 is not continuously arranged.

The planar heating element configured in this way has the following effects. That is, when the heat-uniform heating sheet C is heated and pressed by a hot press in a state where the heat-sensitive heating wires H are wired in a predetermined pattern on the wiring board D, since the heat-uniforming sheet C is pressed against the protrusions 10, Although the thermal expansion of the metal foil 2 is restricted, in the heat-sensitive heating wire H, the heat-melted layer is in a molten state so that the metal foil 2 has an expanding action and at the same time, the heat-sensitive heating wire H has a shrinking action. ing. When the bonding is completed and the press pressure of the hot press is released, a large number of fine wrinkles 12 are generated on the heat-uniformizing sheet C at the boundary between the protruding portion 10 and the portion where the protruding portion 10 is absent. In addition, the strain stress due to the difference between the thermal expansion of the metal foil 2 and the thermal contraction of the heat-sensitive heating wire H is not dispersed and absorbed by the slit 13 and does not grow into a large "bend" or a large "wrinkle". Further, since the protruding portion 10 has a height approximately equal to the outer diameter of the heat-sensitive heating wire H, the heat-sensitive heating wire H is not deformed by the pressure of the hot press, and the protruding portion 10 and the heat equalizing sheet C are not deformed.
The contact area with and the adhesive strength are increased, and the adhesive time is shortened without causing defective adhesion to improve the productivity.

(Effects of the Invention) As described above, according to the planar heating element of the present invention, a heat-sensitive heating wire provided on the wiring board is provided as a means for absorbing slack wrinkles generated in the heat equalizing sheet during hot pressing. Due to the use of the protrusions that have almost the same height, the large "deflection" and large "wrinkle" that occur in the metal foil of the heat equalizing sheet.
And the heat-sensitive heating wire is not deformed,
Adhesion failure does not occur and the adhesion time can be shortened.

[Brief description of drawings]

1 and 2 are an internal perspective view and an overall plan view showing an embodiment of the present invention, FIG. 3 is an explanatory sectional view showing an example of a conventional electric carpet, and FIG. 4 is a conventional planar heat generation. FIG. 5 is a sectional view showing an example of a body, and FIG. 5 is a developed perspective view showing a heat-sensitive heating wire in a conventional sheet heating element. A ... front surface material, B ... back surface material, C ... heat equalizing sheet, D ... wiring board, H ... heat-sensitive heating wire, 10 ... protruding portion, 11 ... gap portion, 12 ... fine wrinkles.

Claims (1)

[Claims] 1. A heat equalizing sheet in which a heat-fusible resin layer is provided on at least one surface of a metal foil, a wiring board, and heat-sensitive heating wires arranged in a predetermined wiring pattern on the wiring board. In a method for manufacturing a planar heating element in which these are heat-pressed and welded in a stacked state, the heat-sensitive heat generation provided on the wiring board as a means for absorbing slack wrinkles generated in the soaking sheet during hot pressing. A method for manufacturing a planar heating element, characterized in that a projecting portion provided between wire wiring patterns and having a height substantially equal to that of the heat-sensitive heating wire is used.